The club was founded on March 25, 1908 by 22 Belorizontino students, being led by Margival Mendes Leal and Mário Toledo as a response to the social discrimination practiced by many clubs elsewhere in Brazil. Despite being founded by upper class founders, the club opened its doors to everyone regardless of social class, quickly establishing itself as a "people's club". As a result, the club has the most supporters in the city and the largest supporters in the state.[1] Atlético is also the oldest club of Belo Horizonte. Atlético play their home games at the Estádio Independência, better known as the Independência, which currently holds up to 23,018 spectators. Atlético's regular kit is black and white striped shirts, with black shorts, accompanied by white socks. Puma are the kit manufacturers currently.

Atlético's first match was against Sport Club Foot Ball, the biggest and oldest club in Belo Horizonte at the time. The match was played on March 21, 1909, and Atlético won 3–0. Furious, Sport's board demanded that Atlético play a rematch the following week to get revenge, to which Atlético agreed. Atlético won again, but this time the score was 4–0. In 1913, the club officially changed its name from Athletico Mineiro Foot Ball Club to Clube Atlético Mineiro. The following year, in 1914, Atlético won its first championship, the Taça Bueno Brandão, a tournament between Atlético, América and Yale. In 1915, the club won the first Minas Gerais State Championship in history, which was organized by the Liga Mineira de Esportes Terrestres.

Circled, The Trio Maldito: Said, Jairo and Mário de Castro, from left to right.

From then on, Atlético's team consisted of 3 of the club's best players in history: Said, Jairo and Mário de Castro. They scored a combined total of 4 goals: 1 from Jairo, 1 from Said and 2 from Mário de Castro. In the 1930s, the club won the state championships of 1931, 1932, 1936, 1938 and 1939. In 1937, Atlético won the first national championship of its history: the Champions Cup (FBF), which included the champions of four states: Fluminense (Rio de Janeiro), Portuguesa (São Paulo), Rio Branco (Espírito Santo), and Atlético.

Atlético dominated the football scene of Minas Gerais State in the 1940s and 1950s, winning no less than 12 state championships between 1940 and 1960, including 5 championships in a row sequence, from 1952 to 1956. In 1950, Atlético accomplished one of the most celebrated achievements in its history by winning the symbolic title of Ice Champion (Campeão do Gelo) after a successful tour in Europe, where the team played against clubs like Schalke 04, Hamburger SV, and RSC Anderlecht.

The 1960s were known as the decade in which the Mineirão Stadium was built, but they were difficult times for the club. During this period, they only managed to win the state champions of 1962 and 1963. It was in the mid-1960s that the rivalry with Cruzeiro became strong, after the blue club won 5 state championships in a row (the first 5 championships of Mineirão era). However, in December 1968, Atletico beat Yugoslavia National Team (runners-up of UEFA Euro 1968) 3-2 in the Mineirão. In October 1969, Atlético beat the Brazilian National Team that would become champions of the 1970 FIFA World Cup by 2–1 at the Mineirão.

It was only in 1970 that Atlético won its first championship in Mineirão Stadium, breaking Cruzeiro's five titles sequence. In 1971, the club won its first and only Brazilian Championship in history. In 1976, Atlético won the State Championship again and also finished in third place in the 1976 Brazilian Championship. They also finished runners-up in the 1977 championship, despite not being defeated for the entire season. In 1978, Atlético won the Champions Cup (CBD), a tournament between the past winners of the Brazilian Championship, defeating São Paulo Futebol Clube in the final.

Since 1977 Atlético made a great team, that would last until the middle of the 1980s, one of the best in its history. This team that had players like Reinaldo, Toninho Cerezo, Éder, Luisinho, Paulo Isidoro, João Leite won the state championship 6 times in a row, from 1978 to 1983, winning also in 1985, 1986, 1988 and 1989. Atlético also had good performances in the Brazilian Championship, having the best campaign for four times 77, 80, 83, 85. Political and arbitration scandals prevented Atlético to win.

In 1977, Reinaldo, the historical scorer of Brazilian championship in that year was forbidden to play the final, supposedly by his insistence in celebrating his goals raising his fist, in a symbol of left politics opposed to Brasil military regimen of the time. Atlético got the 2º place with the best campaign of Brazilian championship ever, finishing with 17 victories and four draws. In 1980, a scandal of arbitration would eliminate Atlético in the final, with Reinaldo receiving red card after scoring twice. In the next year Atlético would be eliminated from Copa Libertadores without losing a match, after having 5 players receiving red card in a game known as "the big stickup". Atlético was also third placed in 1983, 1986 and in the gold cup of 1987.

In the 1990s, Atlético won the state championships in 1991, 1995 and in 1999 and had some good performances in Brazilian Championships, finishing runner-up in 1999, third placed in 1996 and fourth placed in 1994 and 1997. In 1992, Atlético won the CONMEBOL Cup, the club's first official international title, which was won again in 1997. Twice the team had the top goalscorer of Brasileirão, in 1996 with Renaldo (tied with Paulo Nunes) and in 1999 with Guilherme.

The financial situation turned worse in the late 1990s, with a scandal involving the then Atlético's president Paulo Curi and, the 2000s (decade) did not start well for Atlético, as the club had suffered serious crisis. Atlético won only the state championship in 2000, and was runner-up in 2001 and in 2004. In 2000, it reached the Copa Libertadores quarterfinals, and was fourth placed in the Brazilian Championship in 2001, with great players on the team as Cicinho, Gilberto Silva and Valdo Filho, among others. In 2004, Atlético almost got relegation to Série B. 2005 started disastrously, and was the worst year in its history; the club was relegated to Brazilian Second Division.

In 2006 the club won the Brazilian League Série B after a good campaign, qualifying to play the Brazilian League Série A in 2007. That year, Atlético won the Campeonato Mineiro again, defeating their rivals Cruzeiro in the final. After its promotion, the club managed to finish 8th in the 2007 Brasileirão, earning a spot at the Copa Sudamericana 2008.

In 2009, Atlético led the Brasileirão in eight of the thirty-eight rounds, and finished in seventh place. Striker Diego Tardelli was the top goalscorer of the championship (18, alongside Flamengo's Adriano), and the biggest overall of the year in Brazilian football, with 57.

In 2010, the team won his 40th Campeonato Mineiro. In 2012, Atlético commenced another successful era, harkening back to the 1940s, 1950s and 1990s, winning its 41st State Championship without losing a match, including a 3-0 win over their rivals América in the final. They finished the State Championship with an overall record of 11 victories and 4 draws, having won 10 straight matches. Later in that year, Atlético, led by Ronaldinho Atlético finished runner-up in the Brazilian Championship after leading for 15 consecutive rounds. Atlético finished with 72 points overall, was the top goal scoring team in the Championship, and earned a spot in the Group Stages of the Copa Libertadores

In 2013, Atlético once again started strong with 10 straight wins in their first 11 games of the year, with four victories in the Copa Libertadores including six victories in the State Championship, including a 5-2 victory over their rivals América. Atlético reached on July 10, 2013 the Finals of the Copa Libertadores 2013 for the first time in the club's history, defeating Argentinian side Newell's Old Boys in a penalty shootout by a score of 3-2 after losing the first leg by 2-0 and winning the second leg by 2-0.[7] On July 24, 2013, Atlético won the Copa Libertadores for the first time in their history. They defeated Paraguayan side Olimpia of Asuncion in a penalty shootout by a score of 4-3 after losing the first leg by 2-0 and winning the second leg by 2-0.[8]

In 2014, Atlético won its first South American Recopa after beating Argentina‘s Lanús in overtime 4-3. Gustavo Gomez Portillo at the 102nd minute and Victor Ayala at the 111th minute gave the title away with own goals. It was their first Recopa Sudamericana for Atletico after winning the 2013 Copa Libertadores, adding to their two Copa CONMEBOL (1992 and 1997). In the first leg in Buenos Aires, the 'Galo' won 1-0. Meanwhile, Diego Tardelli scored his hundredth goal with the 'Galo' at the 6th minute and Maicosuel at the 37th minute. For the 'granate', the South American champion last year, Ayala (8), Silva (25) and Acosta (90 +3) scored. That last goal, minutes from the final whistle, took the match to extra time.

Despite being founded by upper class founders, the club opened its doors to everyone regardless of social class, quickly establishing itself as a "people's club". As a result, the club has the most supporters in the city and the largest supporters in the state.[1]

Atlético is the club which attracted most people to Mineirão; as of 2002, 20,887,391 people in 1,011 matches. Even with 51 less games than the second placed Cruzeiro, Atlético brought 1,542,884 people more. These stats do not include derbies.

From 2010 until now, Atlético is playing its home matches on smaller arenas like Arena do Jacaré (17,000 people) and the Estádio Independência (25,000 people) because of the renovation of Mineirão, which has a capacity of 62,170 people, for the 2014 FIFA World Cup. However, Atlético's President said, that the club intends to build its own stadium instead of using other arenas.[18]

Atlético plays two derbies in Belo Horizonte: Atlético v América and Atlético v Cruzeiro. Until the 1950s and early 1960s, the biggest derby in Minas Gerais was Atlético vs América, but from the mid-1960s on, Atlético vs. Cruzeiro became the biggest.

The Atlético vs Cruzeiro derby has been played 484 times, with 195 wins for Atlético, 161 wins for Cruzeiro and 128 draws. Atlético vs América has been played 376 times, with 186 wins for Atlético, 100 wins for América and 90 draws. The biggest win against Cruzeiro was 9-2 on November 27, 1927.[19]

The team's mascot, the rooster, is one of the best-known mascots in the country. It was created in the 1940s by Fernando Pierucetti, a cartoonist for "A Folha de Minas" newspaper. He was designated to design a mascot for each of the three greatest clubs in Belo Horizonte. According to Pierucetti, the symbol of Atlético was the rooster because the team used to play with plenty of passion, and would never give up until the end of each match, just like roosters used in cockfights. Another reason is that the most popular hen breed raised in Brazil has mostly black-and-white feathers, thus making the rooster suitable.